The present invention relates generally to multi-station document inserting systems, which assemble batches of documents for insertion into envelopes. More particularly, the present invention is directed towards the control of the input system to adjust the rate at which sheets are input into a high speed multi-station document inserting systems.
Multi-station document inserting systems generally include a plurality of various stations that are configured for specific applications. Typically, such inserting systems, also known as console inserting machines, are manufactured to perform operations customized for a particular customer. Such machines are known in the art and are generally used by organizations, which produce a large volume of mailings where the content of each mail piece may vary.
For instance, inserter systems are used by organizations such as banks, insurance companies and utility companies for producing a large volume of specific mailings where the contents of each mail item are directed to a particular addressee. Additionally, other organizations, such as direct mailers, use inserts for producing a large volume of generic mailings where the contents of each mail item are substantially identical for each addressee. Examples of such inserter systems are the 8 series and 9 series inserter systems available from Pitney Bowes, Inc. of Stamford, Conn.
In many respects the typical inserter system resembles a manufacturing assembly line. Sheets and other raw materials (other sheets, enclosures, and envelopes) enter the inserter system as inputs. Then, a plurality of different modules or workstations in the inserter system work cooperatively to process the sheets until a finished mailpiece is produced. The exact configuration of each inserter system depends upon the needs of each particular customer or installation.
For example, a typical inserter system includes a plurality of serially arranged stations including an envelope feeder, a plurality of insert feeder stations and a burster-folder station. There is a computer generated form or web feeder that feeds continuous form control documents having control coded marks printed thereon to a cutter or burster station for individually separating documents from the web. A control scanner is typically located in the cutting or bursting station for sensing the control marks on the control documents. According to the control marks, these individual documents are accumulated in an accumulating station and then folded in a folding station. Thereafter, the serially arranged insert feeder stations sequentially feed the necessary documents onto a transport deck at each insert station as the control document arrives at the respective station to form a precisely collated stack of documents which is transported to the envelope feeder-insert station where the stack is inserted into the envelope. A typical modem inserter system also includes a control system to synchronize the operation of the overall inserter system to ensure that the collations are properly assembled.
In order for such multi-station inserter systems to process a large number of mailpieces (e.g., 18,000 mailpieces an hour) with each mailpiece having a high average page count collation (at least four (4) pages), it is imperative that the input system of the multi-station inserter system is capable of cycling input documents at extremely high rates (e.g. 72,000 per hour). However, currently there are no commercially available document inserter systems having an input system with the capability to perform such high speed document input cycling. Regarding the input system, existing document inserter systems typically first cut or burst sheets from a web so as to transform the web into individual sheets. These individual sheets may be either processed in a one-up format or merged into a two-up format, typically accomplished by center-slitting the web prior to cutting or bursting into individual sheets. A gap is then generated between the sheets (travelling in either in a one-up or two-up format) to provide proper page breaks enabling collation and accumulation functions. After the sheets are accumulated, they are folded and conveyed downstream for further processing. As previously mentioned, it has been found that this type of described input system is either unable to, or encounters tremendous difficulties, when attempting to provide high page count collations at high cycling speeds.
Therefore, it is an object of the present invention to overcome the difficulties associated with input stations for console inserter systems when providing high page count collations at high cycling speeds.
The present invention provides a system and method for inputting documents in a high speed inserter system to achieve high page count collations. More particularly, the present invention provides for collecting, stacking and re-feeding individual documents after they are fed from a web supply and separated in a cutting station, preparatory to collation and accumulation of the individual documents.
In accordance with the present invention, the input system includes a feeding module for supplying a paper web having the two web portions in side-by-side relationship. A merging module is located downstream in the path of travel from the feeding module and is operational to feed the two web portions in upper-lower relationship so as to reorient the paper web from the side-by-side relationship to an upper-lower relationship. A separating module is located downstream in the path of travel from the merging module and is operational to receive the paper web in the upper-lower relationship and separate the paper web into individual two-up sheets. In order to separate the two-up sheets into one-up sheets, a stacking module is located downstream in the path of travel from the separating module and is configured to receive the two-up sheets, stack the two-up sheets in a sheet pile and individually feed one-up sheets from the stack.
The rate at which one-up sheets are fed from the stack can vary, depending in part on the size of the collations to be inserted downstream. If a series of collations drawn from the stack include a large number of sheets, one-up sheets will be drawn from the stack more quickly. If a series of collations have fewer sheets, one-up sheets will be drawn from the stack less quickly. If two-up sheets are fed into stacking module at a constant speed it is likely that the stack will eventually become over-full or under-full based on the variations in the output speed of the one-up sheets.
Accordingly, in the preferred embodiment of the present invention, the rate of feeding two-up sheets into the stacking module is adjusted as a function of the rate at which one-up sheets are fed out of the stack, and as a function of the deviation of the stack height from a pre-selected nominal stack height.